Dyeing process



Patented May 7, 1946 nynmo PROCESS Cyril M. Croft and Walter H. Hindle, Cumberland, Md., assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application July 3, 1942,

I Serial No. 449,593

3 Claims.

This invention relates to the dyeing oforganic derivative of cellulose textile materials, and relates more particularly to the dyeing of organic derivative of cellulose textile materials f a fairly heavy and/or compact construction.

An object of our invention is to dye organic derivative of cellulose textile materials, and particularly fabric of a fairly heavy and/or compact V structure in a more satisfactory maunen Another object of our invention is to obtain more uniform, level dyeings oforganic derivative of cellulose textile v materials of a fairly heavy and/or compact structure employing winch-dyeing methods. 1

Still another object of our invention is the elimination of overdyed creases, cracking and other defects in dyed fabrics.

Other objects of our invention will'appear from the following detailed description.

Variousprocedures have been employed in the dyeing of textile materialshaving a basis of an organic derivative of cellulose, and particularly fabrics woven oi. yarns of high denier and which n; are of a fairly heavy and/or compact construction, such as sharkskins. Fabrics of the sharkskin type are especially dimcult to dyebecause of their weight and weave. They dye rather slowly, requiring long periods of immersion and manipulation in order to obtain sufficiently deep, level, non-fugitive and non-crocking shades. Fabrics of the sharkskin type are generally dyed by jig dyeingand winch dyeing processes. Jig dyeing, however, is not entirel satisfactory since fabrics dyed in this manner tend to have certain defects, such as shaded selvedges, endedness and overdyed seam bars, which render the fabrics of limited commercial value and application, When such fabric is processed by winch dyeing methods. the fabric usually is free of defects resulting from jig dyeing but the heavy and relatively still character of the fabric makes winch dyeing rather uncertain due to the fact that the fabrics may crack. 1 In addition, such heavy fabric frequently develops overdyed winch creases due to the 'piling' and folding of the fabric, during the winch dyeing operation. Such overdyed creases are, of course. a distinct disadvantage and the elimination of this type of defect has been the subject of much research and experimentation.

We have now discovered that organic derivative of cellulose fabrics woven of yarns of high denier dyeing methods and dyed fabrics may be obtained which are free from the above mentioned defects,

such as overdyed creases and cracking. In accordance with our invention, these highly desirable results are obtained if, prior to dyeing, the fabrics to be dyed are first subjected to impregnation with Turkey red oil, then dried and the dried fabrics subjected to scouring. Our novel treatment imparts a desirable soft, limp and pliable hand to the fabrics in place of the somewhat stiff and heavy hand previously obtained. When the treated, scoured fabrics are dyed in the usual manner on a winch with a suitable dye-bath, the

fabrics are dyed in level, even shades, and are substantially fre of overdyedcreases, cracking,

. and other defects normally associated with winch dyed fabrics of like construction.

The Turkey red oil may be applied to the fabrics .by padding, spraying, dipping or by any other convenient method of impregnation. The Turkey red oil is preferably applied at elevated temperature .in a relatively concentrated form. The

amount applied may be adjusted by passing the ffabric between nipping or padding rolls which are under suitable adjustment to permit the desired amount to be retained in the fabric. The amount applied may be from to 60% on the weight of the fabric and the temperature of the Turkey red oil during application may be maintained at from to 80 C.', preferably about 60 C. After the desired amount of Turkey red oil has been applied, the fabric is subjected to a drying removed by scouring which may be carried out conveniently on a winch or on any other apparatus applicable to the scouring of. the fabric. The

scouring agent employed preferably comprises a mixture of Turkey red oil, xylene and water in the proportion o f 20 to 25 parts of Turkey red oil, 4 to 6 parts by xylene and to I0 parts of water. The scouring bath may be made up by employing the above scouring agent in water in a concentration of from 0.1 to 0.5% on the weight of the.

bath. After scouring for from Ho 2 hours, during which time the scouring bath may be maintained at 60 to C.. the sticky and gummy hand gives way to a verysoft, limp hand, leaving the fabric highly pliable. In this condition. the fabric can encountered in the dyeing of fabrics of compact and/or heavy construction. In addition to a scouring bath comprising Turkey red oil and xylene, other scouring agents, such as fatty alcohol sulfates, for example, Gardinol WA and Modinal ES" or other scouring agents, such as Igepon T and Parapon SA" may be employed.

'In order further to illustrate our invention, but without being limited thereto, the following example is given:

Example A cellulose acetate fabric of a basket weave and having 96 ends per inch of 300 denier 80 filament cellulose acetate yarns in the warp, and 38 picks per inch of 600 denier, 160 filament yarns in the filling, is padded with concentrated Turkey red oil at 60 C. The nip of the padding rolls is so adjusted as to leave 50% of the oil by weight on the yarnsr The fabric is dried with heated air at 90 C. to 95 C. After standing overnight, that is for about 12 hours, the fabric is scoured on a winch for 2 hours in an aqueous scouring bath containing 0.1% by weight of a scouring agent comprising 25 parts of Turkey red oil, 5 parts of xylene and 70 parts of water.

The fabric is then dyed in a dyebath suitable for dyeing cellulose acetate. After dyeing is completed the dyed frabric is found to be free of over-dyed creases, cracking, and other defects. When'a fabric of this construction is dyed on-a winch without our novel treatment, the resulting fabric is seriously degraded due to numerous long over-dyedwinch creases.

While our invention is particularly directedto the treatment of organic derivative of cellulose fabrics prior to dyeing, other organic derivative of cellulose textile materials such as, for example, yarns, hanks, staple fibers associated in the form of a top, or textilematerials in other forms may also be treated by our process and improved dyeing properties imparted thereto,

access? The organic derivative of cellulose fabrics, yarns, tops, etc. which may be treated in accordance with our invention may be cellulose esters or cellulose ethers. Examples of cellulose esters are cellulose acetate, cellulose propionate, cellulose butyrate, and mixed esters, such as cellulose acetate-propionate and cellulose acetate-butyrate, while examples of cellulose ethers are ethyl cellulose and benzyl cellulose,

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Method for the coloration of fabrics, which comprises impregnating a fabric of comparatively compact construction made of or containing yarns of cellulose acetate with Turkey red oil in such concentration that the amount applied to the fabric is from 35 to 60% on the weight of the fabric, drying said impregnated fabric, scouroil at a temperature of about C. to impregnate said fabric, drying said impregnated fabric with heated air at a temperature of from to C., allowing the dried fabric to stand, scouring the fabric and subjecting thetreated fabric to a winch dyeing operation. F

. CYRIL M. CROFT.

WALTER H. 

